Peculiarities of gas and dust production rates in comets P/Halley (1986 III), P/Giacobini-Zinner (1985 XIII), P/Hartley-Good (1985 XVII) and P/Thiele (1985 XIX)

An IHW narrow‐band photometry of comets P/Halley (1986 III), P/Giacobini‐Zinner (1985 XIII), P/Hartley‐Good (1985 XVII) and P/Thiele (1985 XIX) is presented. Molecular column densities and production rates of CN, C2, and C3 species observed in the coma are calculated in the framework of the Haser model. A comparative analysis of gas and dust production rates in the atmospheres of these comets is given. The effective comet nuclear radii have been estimated by different methods: for comet P/Hartley‐Good Reff ∼ 1·7 km, for P/Thiele Reff ∼ 2 km and for P/Giacobini‐Zinner Reff ∼ 1·3 km.